The Russian S-400 Missile Defence System is back in the news as both Saudi Arabia and Qatar have now expressed interest in buying what is quite possibly the world’s most advanced ground-to-air missile defence system. While Saudi Arabia has threatened to strike Qatar if Russia delivers the S-400, like most threats between Riyadh and Doha, this is clearly a bluff.

One of the crucial things about two rival neighbours having the S-400s is that such a scenario does not give an aggressive advantage to either side. As the S-400 systems are purely defensive weapons, all it means is that neither side’s attempted strikes would likely have a great deal of impact. Thus, if Russia were to deliver S-400s to both Saudi Arabia and Qatar, all it would do is neutralise the ability of the rivals to inflict much damage on t he other – it would be a kind of equaliser.

Unlike the Saudi/Qatari rivalry which will likely never result in a traditional war, the decades long confrontational relationship between Syria and “Israel” has resulted in several wars, while the current Syria conflict is intrinsically related to Tel Aviv’s desire to destroy its Arab Nationalist rival.

In spite of Russia publicly toying with the idea of delivering its second most advanced missile defence system, the S-300s to Syria, Tel Aviv’s protestations led Russia to confirm that no S-300s will be delivered to Syria. The move shocked many semi-informed observers who are either ignorant of or pretend to be ignorant of Moscow’s close friendship with Tel Aviv. Of course, Russia has an even older friendship with Damascus and therefore a different kind of compromise could and perhaps should be possible.

If both Syria and “Israel” were given not just S-300s but S-4000s, it could help to neutralise the ability of each rival to inflict serious harm on the other. As Turkey inches closer to hostile relations with “Israel” Tel Aviv will have to learn to live with Turkey’s soon to be delivered S-400s and if Saudi Arabia and Qatar will both be balanced in their feud by the mutual presence of S-400s, then the same is theoretically possible in respect of Syria and “Israel”.

Of course, if Russia were to tempt both Tel Aviv and Damascus with such an offer, both sides would almost certainly loudly object to the other having S-400s, just as Saudi Arabia is objecting to Qatar’s S-400 deal. But in reality, if such deliveries were to be made, it would render many of the offensive weapons on both sides obsolete – at least until the United States could attempt and build offensive missile systems that can penetrate the S-400s shield, something which thus far few weapons builders have been able to accomplish.

In this sense, just as the phenomenon of two rivals having nuclear weapons tends to dissuade either side from attacking the other due to the doctrine of mutually assured destruction, the presence of S-400 systems in neighbouring rivals could witness the development of the doctrine of mutually assured protection. Therefore just as is the case with Qatar and Saudi Arabia, giving both Syria and “Israel” S-400s could dissuade both sides from attacking one another given that such attacks would likely do little damage to the other side due to the extreme accuracy of the S-400s.

While there is little doubt that neither Syria nor “Israel” will have any S-400 systems of their own anytime soon, the entire scenario does serve to demonstrate how a good defensive system can help to neutralise a regional rivalry or arms race, even if Saudi Arabia and Qatar haven’t yet grasped this concept.